Dry cleaning for birds

Friday, 30 April 1999 C.Johnson, The Lab

The days of using detergent to clean birds caught in oil spills may soon be over. Australian scientists have discovered iron powder and magnets do the job just as well without destroying the feathers' waterproof properties.

A fine iron powder sprinkled on the feathers and then combed out with a magnet removes the oil because it sticks better to the iron than the birds' plumage, the researchers from Victoria University of Technology found.

Experiments on duck feathers coated with different grades of oil showed the first coating and combing removed at least 60 per cent of the most viscous oils and nearly 90 per cent of light crude oils, the latest New Scientist magazine reports.

After the procedure was repeated 10 times, as little as 3 per cent of the contaminants remained, an efficiency lead researcher John Orbell says he found "quite amazing".

Washing birds with soapy water is slower and requires more handling of the birds, whereas the dry cleaning process takes a matter of minutes, Dr Orbell says.

A skilled operator might wash a bird using conventional techniques in about 15 minutes, but this is normally followed by a rehabilitation process of up to several weeks, designed to allow the natural recovery of the feathers' waterproofing.

Preventing the feather damage in the first place would be a major step forward. For birds like penguins which sleep in water, oil contamination even as small as the size of a coin can be enough for water to seep in and kill the bird from hypothermia.

Most of the team's work so far has been on isolated duck feathers, and on penguins killed by foxes on Phillip Island off the Victorian coast. But field trials on live penguins on the island have just begun.

The iron powder was "close to ideal" because it was cheap, non-toxic and a non-irritant, Dr Orbell said.

"We would expect to recover all of it [from the bird's feathers]. But even if we don't, it's very benign. It degrades to iron oxide, which is an environmental mineral anyway."

The researchers are now working with the Australian company Alpha Magnetics to develop a portable field unit so rescuers can remove the bulk of the contamination on the spot.